/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package com.sun.org.apache.bcel.internal.generic;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache BCEL" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
 *    written permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache BCEL", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

import com.sun.org.apache.bcel.internal.Constants;

/**
 * Instances of this class may be used, e.g., to generate typed
 * versions of instructions. Its main purpose is to be used as the
 * byte code generating backend of a compiler. You can subclass it to
 * add your own create methods.
 *
 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 * @see Constants
 */
public class InstructionFactory
    implements InstructionConstants, java.io.Serializable {

  protected ClassGen cg;
  protected ConstantPoolGen cp;

  public InstructionFactory(ClassGen cg, ConstantPoolGen cp) {
    this.cg = cg;
    this.cp = cp;
  }

  /**
   * Initialize with ClassGen object
   */
  public InstructionFactory(ClassGen cg) {
    this(cg, cg.getConstantPool());
  }

  /**
   * Initialize just with ConstantPoolGen object
   */
  public InstructionFactory(ConstantPoolGen cp) {
    this(null, cp);
  }

  /**
   * Create an invoke instruction.
   *
   * @param class_name name of the called class
   * @param name name of the called method
   * @param ret_type return type of method
   * @param arg_types argument types of method
   * @param kind how to invoke, i.e., INVOKEINTERFACE, INVOKESTATIC, INVOKEVIRTUAL, or
   * INVOKESPECIAL
   * @see Constants
   */
  public InvokeInstruction createInvoke(String class_name, String name, Type ret_type,
      Type[] arg_types, short kind) {
    int index;
    int nargs = 0;
    String signature = Type.getMethodSignature(ret_type, arg_types);

    for (int i = 0; i < arg_types.length; i++) // Count size of arguments
    {
      nargs += arg_types[i].getSize();
    }

    if (kind == Constants.INVOKEINTERFACE) {
      index = cp.addInterfaceMethodref(class_name, name, signature);
    } else {
      index = cp.addMethodref(class_name, name, signature);
    }

    switch (kind) {
      case Constants.INVOKESPECIAL:
        return new INVOKESPECIAL(index);
      case Constants.INVOKEVIRTUAL:
        return new INVOKEVIRTUAL(index);
      case Constants.INVOKESTATIC:
        return new INVOKESTATIC(index);
      case Constants.INVOKEINTERFACE:
        return new INVOKEINTERFACE(index, nargs + 1);
      default:
        throw new RuntimeException("Oops: Unknown invoke kind:" + kind);
    }
  }

  /**
   * Create a call to the most popular System.out.println() method.
   *
   * @param s the string to print
   */
  public InstructionList createPrintln(String s) {
    InstructionList il = new InstructionList();
    int out = cp.addFieldref("java.lang.System", "out",
        "Ljava/io/PrintStream;");
    int println = cp.addMethodref("java.io.PrintStream", "println",
        "(Ljava/lang/String;)V");

    il.append(new GETSTATIC(out));
    il.append(new PUSH(cp, s));
    il.append(new INVOKEVIRTUAL(println));

    return il;
  }

  /**
   * Uses PUSH to push a constant value onto the stack.
   *
   * @param value must be of type Number, Boolean, Character or String
   */
  public Instruction createConstant(Object value) {
    PUSH push;

    if (value instanceof Number) {
      push = new PUSH(cp, (Number) value);
    } else if (value instanceof String) {
      push = new PUSH(cp, (String) value);
    } else if (value instanceof Boolean) {
      push = new PUSH(cp, (Boolean) value);
    } else if (value instanceof Character) {
      push = new PUSH(cp, (Character) value);
    } else {
      throw new ClassGenException("Illegal type: " + value.getClass());
    }

    return push.getInstruction();
  }

  private static class MethodObject {

    Type[] arg_types;
    Type result_type;
    String[] arg_names;
    String class_name;
    String name;
    int access;

    MethodObject(String c, String n, Type r, Type[] a, int acc) {
      class_name = c;
      name = n;
      result_type = r;
      arg_types = a;
      access = acc;
    }
  }

  private InvokeInstruction createInvoke(MethodObject m, short kind) {
    return createInvoke(m.class_name, m.name, m.result_type, m.arg_types, kind);
  }

  private static MethodObject[] append_mos = {
      new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER,
          new Type[]{Type.STRING}, Constants.ACC_PUBLIC),
      new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER,
          new Type[]{Type.OBJECT}, Constants.ACC_PUBLIC),
      null, null, // indices 2, 3
      new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER,
          new Type[]{Type.BOOLEAN}, Constants.ACC_PUBLIC),
      new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER,
          new Type[]{Type.CHAR}, Constants.ACC_PUBLIC),
      new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER,
          new Type[]{Type.FLOAT}, Constants.ACC_PUBLIC),
      new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER,
          new Type[]{Type.DOUBLE}, Constants.ACC_PUBLIC),
      new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER,
          new Type[]{Type.INT}, Constants.ACC_PUBLIC),
      new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER, // No append(byte)
          new Type[]{Type.INT}, Constants.ACC_PUBLIC),
      new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER, // No append(short)
          new Type[]{Type.INT}, Constants.ACC_PUBLIC),
      new MethodObject("java.lang.StringBuffer", "append", Type.STRINGBUFFER,
          new Type[]{Type.LONG}, Constants.ACC_PUBLIC)
  };

  private static final boolean isString(Type type) {
    return ((type instanceof ObjectType) &&
        ((ObjectType) type).getClassName().equals("java.lang.String"));
  }

  public Instruction createAppend(Type type) {
    byte t = type.getType();

    if (isString(type)) {
      return createInvoke(append_mos[0], Constants.INVOKEVIRTUAL);
    }

    switch (t) {
      case Constants.T_BOOLEAN:
      case Constants.T_CHAR:
      case Constants.T_FLOAT:
      case Constants.T_DOUBLE:
      case Constants.T_BYTE:
      case Constants.T_SHORT:
      case Constants.T_INT:
      case Constants.T_LONG
          :
        return createInvoke(append_mos[t], Constants.INVOKEVIRTUAL);
      case Constants.T_ARRAY:
      case Constants.T_OBJECT:
        return createInvoke(append_mos[1], Constants.INVOKEVIRTUAL);
      default:
        throw new RuntimeException("Oops: No append for this type? " + type);
    }
  }

  /**
   * Create a field instruction.
   *
   * @param class_name name of the accessed class
   * @param name name of the referenced field
   * @param type type of field
   * @param kind how to access, i.e., GETFIELD, PUTFIELD, GETSTATIC, PUTSTATIC
   * @see Constants
   */
  public FieldInstruction createFieldAccess(String class_name, String name, Type type, short kind) {
    int index;
    String signature = type.getSignature();

    index = cp.addFieldref(class_name, name, signature);

    switch (kind) {
      case Constants.GETFIELD:
        return new GETFIELD(index);
      case Constants.PUTFIELD:
        return new PUTFIELD(index);
      case Constants.GETSTATIC:
        return new GETSTATIC(index);
      case Constants.PUTSTATIC:
        return new PUTSTATIC(index);

      default:
        throw new RuntimeException("Oops: Unknown getfield kind:" + kind);
    }
  }

  /**
   * Create reference to `this'
   */
  public static Instruction createThis() {
    return new ALOAD(0);
  }

  /**
   * Create typed return
   */
  public static ReturnInstruction createReturn(Type type) {
    switch (type.getType()) {
      case Constants.T_ARRAY:
      case Constants.T_OBJECT:
        return ARETURN;
      case Constants.T_INT:
      case Constants.T_SHORT:
      case Constants.T_BOOLEAN:
      case Constants.T_CHAR:
      case Constants.T_BYTE:
        return IRETURN;
      case Constants.T_FLOAT:
        return FRETURN;
      case Constants.T_DOUBLE:
        return DRETURN;
      case Constants.T_LONG:
        return LRETURN;
      case Constants.T_VOID:
        return RETURN;

      default:
        throw new RuntimeException("Invalid type: " + type);
    }
  }

  private static final ArithmeticInstruction createBinaryIntOp(char first, String op) {
    switch (first) {
      case '-':
        return ISUB;
      case '+':
        return IADD;
      case '%':
        return IREM;
      case '*':
        return IMUL;
      case '/':
        return IDIV;
      case '&':
        return IAND;
      case '|':
        return IOR;
      case '^':
        return IXOR;
      case '<':
        return ISHL;
      case '>':
        return op.equals(">>>") ? (ArithmeticInstruction) IUSHR :
            (ArithmeticInstruction) ISHR;
      default:
        throw new RuntimeException("Invalid operand " + op);
    }
  }

  private static final ArithmeticInstruction createBinaryLongOp(char first, String op) {
    switch (first) {
      case '-':
        return LSUB;
      case '+':
        return LADD;
      case '%':
        return LREM;
      case '*':
        return LMUL;
      case '/':
        return LDIV;
      case '&':
        return LAND;
      case '|':
        return LOR;
      case '^':
        return LXOR;
      case '<':
        return LSHL;
      case '>':
        return op.equals(">>>") ? (ArithmeticInstruction) LUSHR :
            (ArithmeticInstruction) LSHR;
      default:
        throw new RuntimeException("Invalid operand " + op);
    }
  }

  private static final ArithmeticInstruction createBinaryFloatOp(char op) {
    switch (op) {
      case '-':
        return FSUB;
      case '+':
        return FADD;
      case '*':
        return FMUL;
      case '/':
        return FDIV;
      default:
        throw new RuntimeException("Invalid operand " + op);
    }
  }

  private static final ArithmeticInstruction createBinaryDoubleOp(char op) {
    switch (op) {
      case '-':
        return DSUB;
      case '+':
        return DADD;
      case '*':
        return DMUL;
      case '/':
        return DDIV;
      default:
        throw new RuntimeException("Invalid operand " + op);
    }
  }

  /**
   * Create binary operation for simple basic types, such as int and float.
   *
   * @param op operation, such as "+", "*", "<<", etc.
   */
  public static ArithmeticInstruction createBinaryOperation(String op, Type type) {
    char first = op.toCharArray()[0];

    switch (type.getType()) {
      case Constants.T_BYTE:
      case Constants.T_SHORT:
      case Constants.T_INT:
      case Constants.T_CHAR:
        return createBinaryIntOp(first, op);
      case Constants.T_LONG:
        return createBinaryLongOp(first, op);
      case Constants.T_FLOAT:
        return createBinaryFloatOp(first);
      case Constants.T_DOUBLE:
        return createBinaryDoubleOp(first);
      default:
        throw new RuntimeException("Invalid type " + type);
    }
  }

  /**
   * @param size size of operand, either 1 (int, e.g.) or 2 (double)
   */
  public static StackInstruction createPop(int size) {
    return (size == 2) ? (StackInstruction) POP2 :
        (StackInstruction) POP;
  }

  /**
   * @param size size of operand, either 1 (int, e.g.) or 2 (double)
   */
  public static StackInstruction createDup(int size) {
    return (size == 2) ? (StackInstruction) DUP2 :
        (StackInstruction) DUP;
  }

  /**
   * @param size size of operand, either 1 (int, e.g.) or 2 (double)
   */
  public static StackInstruction createDup_2(int size) {
    return (size == 2) ? (StackInstruction) DUP2_X2 :
        (StackInstruction) DUP_X2;
  }

  /**
   * @param size size of operand, either 1 (int, e.g.) or 2 (double)
   */
  public static StackInstruction createDup_1(int size) {
    return (size == 2) ? (StackInstruction) DUP2_X1 :
        (StackInstruction) DUP_X1;
  }

  /**
   * @param index index of local variable
   */
  public static LocalVariableInstruction createStore(Type type, int index) {
    switch (type.getType()) {
      case Constants.T_BOOLEAN:
      case Constants.T_CHAR:
      case Constants.T_BYTE:
      case Constants.T_SHORT:
      case Constants.T_INT:
        return new ISTORE(index);
      case Constants.T_FLOAT:
        return new FSTORE(index);
      case Constants.T_DOUBLE:
        return new DSTORE(index);
      case Constants.T_LONG:
        return new LSTORE(index);
      case Constants.T_ARRAY:
      case Constants.T_OBJECT:
        return new ASTORE(index);
      default:
        throw new RuntimeException("Invalid type " + type);
    }
  }

  /**
   * @param index index of local variable
   */
  public static LocalVariableInstruction createLoad(Type type, int index) {
    switch (type.getType()) {
      case Constants.T_BOOLEAN:
      case Constants.T_CHAR:
      case Constants.T_BYTE:
      case Constants.T_SHORT:
      case Constants.T_INT:
        return new ILOAD(index);
      case Constants.T_FLOAT:
        return new FLOAD(index);
      case Constants.T_DOUBLE:
        return new DLOAD(index);
      case Constants.T_LONG:
        return new LLOAD(index);
      case Constants.T_ARRAY:
      case Constants.T_OBJECT:
        return new ALOAD(index);
      default:
        throw new RuntimeException("Invalid type " + type);
    }
  }

  /**
   * @param type type of elements of array, i.e., array.getElementType()
   */
  public static ArrayInstruction createArrayLoad(Type type) {
    switch (type.getType()) {
      case Constants.T_BOOLEAN:
      case Constants.T_BYTE:
        return BALOAD;
      case Constants.T_CHAR:
        return CALOAD;
      case Constants.T_SHORT:
        return SALOAD;
      case Constants.T_INT:
        return IALOAD;
      case Constants.T_FLOAT:
        return FALOAD;
      case Constants.T_DOUBLE:
        return DALOAD;
      case Constants.T_LONG:
        return LALOAD;
      case Constants.T_ARRAY:
      case Constants.T_OBJECT:
        return AALOAD;
      default:
        throw new RuntimeException("Invalid type " + type);
    }
  }

  /**
   * @param type type of elements of array, i.e., array.getElementType()
   */
  public static ArrayInstruction createArrayStore(Type type) {
    switch (type.getType()) {
      case Constants.T_BOOLEAN:
      case Constants.T_BYTE:
        return BASTORE;
      case Constants.T_CHAR:
        return CASTORE;
      case Constants.T_SHORT:
        return SASTORE;
      case Constants.T_INT:
        return IASTORE;
      case Constants.T_FLOAT:
        return FASTORE;
      case Constants.T_DOUBLE:
        return DASTORE;
      case Constants.T_LONG:
        return LASTORE;
      case Constants.T_ARRAY:
      case Constants.T_OBJECT:
        return AASTORE;
      default:
        throw new RuntimeException("Invalid type " + type);
    }
  }


  /**
   * Create conversion operation for two stack operands, this may be an I2C, instruction, e.g.,
   * if the operands are basic types and CHECKCAST if they are reference types.
   */
  public Instruction createCast(Type src_type, Type dest_type) {
    if ((src_type instanceof BasicType) && (dest_type instanceof BasicType)) {
      byte dest = dest_type.getType();
      byte src = src_type.getType();

      if (dest == Constants.T_LONG && (src == Constants.T_CHAR || src == Constants.T_BYTE ||
          src == Constants.T_SHORT)) {
        src = Constants.T_INT;
      }

      String[] short_names = {"C", "F", "D", "B", "S", "I", "L"};

      String name =
          "com.sun.org.apache.bcel.internal.generic." + short_names[src - Constants.T_CHAR] +
              "2" + short_names[dest - Constants.T_CHAR];

      Instruction i = null;
      try {
        i = (Instruction) java.lang.Class.forName(name).newInstance();
      } catch (Exception e) {
        throw new RuntimeException("Could not find instruction: " + name);
      }

      return i;
    } else if ((src_type instanceof ReferenceType) && (dest_type instanceof ReferenceType)) {
      if (dest_type instanceof ArrayType) {
        return new CHECKCAST(cp.addArrayClass((ArrayType) dest_type));
      } else {
        return new CHECKCAST(cp.addClass(((ObjectType) dest_type).getClassName()));
      }
    } else {
      throw new RuntimeException("Can not cast " + src_type + " to " + dest_type);
    }
  }

  public GETFIELD createGetField(String class_name, String name, Type t) {
    return new GETFIELD(cp.addFieldref(class_name, name, t.getSignature()));
  }

  public GETSTATIC createGetStatic(String class_name, String name, Type t) {
    return new GETSTATIC(cp.addFieldref(class_name, name, t.getSignature()));
  }

  public PUTFIELD createPutField(String class_name, String name, Type t) {
    return new PUTFIELD(cp.addFieldref(class_name, name, t.getSignature()));
  }

  public PUTSTATIC createPutStatic(String class_name, String name, Type t) {
    return new PUTSTATIC(cp.addFieldref(class_name, name, t.getSignature()));
  }

  public CHECKCAST createCheckCast(ReferenceType t) {
    if (t instanceof ArrayType) {
      return new CHECKCAST(cp.addArrayClass((ArrayType) t));
    } else {
      return new CHECKCAST(cp.addClass((ObjectType) t));
    }
  }

  public INSTANCEOF createInstanceOf(ReferenceType t) {
    if (t instanceof ArrayType) {
      return new INSTANCEOF(cp.addArrayClass((ArrayType) t));
    } else {
      return new INSTANCEOF(cp.addClass((ObjectType) t));
    }
  }

  public NEW createNew(ObjectType t) {
    return new NEW(cp.addClass(t));
  }

  public NEW createNew(String s) {
    return createNew(new ObjectType(s));
  }

  /**
   * Create new array of given size and type.
   *
   * @return an instruction that creates the corresponding array at runtime, i.e. is an
   * AllocationInstruction
   */
  public Instruction createNewArray(Type t, short dim) {
    if (dim == 1) {
      if (t instanceof ObjectType) {
        return new ANEWARRAY(cp.addClass((ObjectType) t));
      } else if (t instanceof ArrayType) {
        return new ANEWARRAY(cp.addArrayClass((ArrayType) t));
      } else {
        return new NEWARRAY(((BasicType) t).getType());
      }
    } else {
      ArrayType at;

      if (t instanceof ArrayType) {
        at = (ArrayType) t;
      } else {
        at = new ArrayType(t, dim);
      }

      return new MULTIANEWARRAY(cp.addArrayClass(at), dim);
    }
  }

  /**
   * Create "null" value for reference types, 0 for basic types like int
   */
  public static Instruction createNull(Type type) {
    switch (type.getType()) {
      case Constants.T_ARRAY:
      case Constants.T_OBJECT:
        return ACONST_NULL;
      case Constants.T_INT:
      case Constants.T_SHORT:
      case Constants.T_BOOLEAN:
      case Constants.T_CHAR:
      case Constants.T_BYTE:
        return ICONST_0;
      case Constants.T_FLOAT:
        return FCONST_0;
      case Constants.T_DOUBLE:
        return DCONST_0;
      case Constants.T_LONG:
        return LCONST_0;
      case Constants.T_VOID:
        return NOP;

      default:
        throw new RuntimeException("Invalid type: " + type);
    }
  }

  /**
   * Create branch instruction by given opcode, except LOOKUPSWITCH and TABLESWITCH.
   * For those you should use the SWITCH compound instruction.
   */
  public static BranchInstruction createBranchInstruction(short opcode, InstructionHandle target) {
    switch (opcode) {
      case Constants.IFEQ:
        return new IFEQ(target);
      case Constants.IFNE:
        return new IFNE(target);
      case Constants.IFLT:
        return new IFLT(target);
      case Constants.IFGE:
        return new IFGE(target);
      case Constants.IFGT:
        return new IFGT(target);
      case Constants.IFLE:
        return new IFLE(target);
      case Constants.IF_ICMPEQ:
        return new IF_ICMPEQ(target);
      case Constants.IF_ICMPNE:
        return new IF_ICMPNE(target);
      case Constants.IF_ICMPLT:
        return new IF_ICMPLT(target);
      case Constants.IF_ICMPGE:
        return new IF_ICMPGE(target);
      case Constants.IF_ICMPGT:
        return new IF_ICMPGT(target);
      case Constants.IF_ICMPLE:
        return new IF_ICMPLE(target);
      case Constants.IF_ACMPEQ:
        return new IF_ACMPEQ(target);
      case Constants.IF_ACMPNE:
        return new IF_ACMPNE(target);
      case Constants.GOTO:
        return new GOTO(target);
      case Constants.JSR:
        return new JSR(target);
      case Constants.IFNULL:
        return new IFNULL(target);
      case Constants.IFNONNULL:
        return new IFNONNULL(target);
      case Constants.GOTO_W:
        return new GOTO_W(target);
      case Constants.JSR_W:
        return new JSR_W(target);
      default:
        throw new RuntimeException("Invalid opcode: " + opcode);
    }
  }

  public void setClassGen(ClassGen c) {
    cg = c;
  }

  public ClassGen getClassGen() {
    return cg;
  }

  public void setConstantPool(ConstantPoolGen c) {
    cp = c;
  }

  public ConstantPoolGen getConstantPool() {
    return cp;
  }
}
